Additional Test Methods for Dielectric Testing

The previous post provided test methods for dielectric breakdown and dielectric strength at commercial ac frequencies, i.e., 60Hz. Here are two additional test methods to be used for dc testing and impulse testing.

IEC 60243-2 gives requirements additional to those in IEC 60243-1 for the determination of the electric strength of solid insulating materials under direct voltage stress.

For impulse testing, see IEC 60243-3, which gives requirements additional to those in IEC 60243-1 for the determination of the electric strength of solid insulating materials under 1,2/50 ms impulse voltage stress.

For reference:
IEC 60243-2 Electric Strength of Insulating Materials - Test Methods - Part 2: Additional Requirements for Tests Using Direct Voltage

IEC 60243-3 Electric Strength of Insulating Materials - Test Methods - Part 3: Additional Requirements for 1,2/50 us Impulse Tests

Standard Test Methods for Dielectric Breakdown Voltage and Dielectric Strength

Standards that applies to testing for dielectric breakdown and dielectric strength are from ASTM and the IEC.

ASTM test method D 149 is most commonly used to determine the dielectric breakdown voltage through the thickness of a test specimen (puncture). It may also be used to determine dielectric breakdown voltage along the interface between a solid specimen and a gaseous or liquid surrounding medium (flash-over).

This test method is similar to IEC Publication 60243-1. All procedures in this method are included in IEC 60243-1. Differences between this method and IEC 60243-1 are largely editorial. Gives test methods for the determination of the short-time electric strength of solid insulating materials at power frequencies between 48 Hz and 62 Hz. It does not consider the testing of liquids and gases. It does, however, include methods for the determination of breakdown voltages along the surfaces of solid insulating materials are included.

Test method D 149 is not intended for use in determining intrinsic dielectric strength, direct-voltage dielectric strength, or thermal failure under electrical stress (see Test Method D 3151). That test method covers the determination of the thermal failure of solid electrical insulating materials subjected to electric stress at commercial power frequencies.

For reference:

ASTM D 149 REV A: Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies

ASTM D 3151: Standard Test Method for Thermal Failure of Solid Electrical Insulating Materials under Electric Stress

IEC 60243-1: Electrical Strength of Insulating Materials - Test Methods - Part 1: Tests at Power Frequencies